Universal display panel

ABSTRACT

A programmable, lighted display panel device is disclosed comprising a translucent panel, individual areas of which can be back-lighted according to programmed circuitry including stepping switch means responsive alternatively to pushbutton selection switch means or single step switch means to control illumination of the pushbuttons and to control a program switch which, together with a wiring patch board, effect energization of predetermined groups of panel illuminating lamps. The circuitry includes means for regulating lamp brightness, for preventing lamp flicker during stepping, and for preventing undue inrush current through lamp-controlling contacts.

United States Patent [72] Inventor Donald E. Reed Winter Park, Fla. [21] Appl. No. 775,082 [22] Filed Nov. 12, 1968 [45] Patented Apr. 6, 1971 [73] Assignee The United States of America as represented by the Secretary of the Navy [54] UNIVERSAL DISPLAY PANEL 12 Claims, 6 Drawing Figs.

[5 2] US. Cl 340/339, 40/132, 340/225, 340/325 [51] Int. Cl 609i 13/04 [50] Field of Search 340/225, 338, 339,164, 325; 40/132 (X), 106.52; 35/(Inquired) [5 6] References Cited UNITED STATES PATENTS 2,504,851 4/ 1950 Vesconte 340/225X 2,952,079 9/1960 Koch 40/132X 3,051,937 8/1962 Arthur 340/325X 3,156,985 11/1964 Bliss et al.... 40/132X 3,171,114 2/1965 Butler et a1. 340/225X 3,478,345 11/1969 Greenwald 340/338 .Primary Examiner-Thomas B. Habecker Assistant Examiner-David L. Trafton Atlorneys-Joseph C. Warfield, John W. Pease and Harvey A.

David SHEET 1 [IF 5 Donald E. Reed INVENTOR.

P5 BY m 4/ iz/meyd PATENTED APR 6191: V

" sum a nr 5 UNIVERSAL DISPLAY PANEL The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION This invention relates to lighted display or instructional panels and more particularly to such panels wherein predetermined areas of a chart or diagram thereon may be illuminated in a selected sequence in order to assist in focusing the attention of a viewer on those areas, for example, during classroom instruction. Various forms of sequentially lighted panels have been utilized heretofore either for instructional aids or advertising purposes. These have generally been confined to two types, one wherein the program is controlled by selectively manually actuating switches which control energization of desired areas of a panel, and the other wherein a timer-motordriven switch or a manually operated switch causes the sequential lighting of areas in a fixed, predetermined sequence.

The former requires a great deal of concentration on the part of the instructor who must find and operate the proper switch at the proper time to carry forth the lighting sequence which corresponds to his presentation, while the latter type is limited to a fixed, predetermined sequence which is difficult and costly to have programmed.

Each of the prior art devices lacks a convenient means whereby the instructor or individual students may participate by modifying the sequence of illumination at any desired time, for example, to illuminate an area, either out of sequence or which is not in the predetermined sequence, as an aid to illustrating a question or answer or other point of discussion.

SUMMARY OF THE INVENTION With the foregoing in mind, it is a principal object of this invention to provide an improved display device of the type wherein areas of a panel may be lighted in accordance with a predetermined program or sequence whereby portions of diagrams, charts, or the like on the panel are illuminated in a desired sequence, for example to accompany the progress of a verbal presentation by a classroom instructor, and which display device may be conveniently programmed by the instructor or other user without special tools, equipment or extensive training.

Another object of this invention is the provision of a backlighted display device of the foregoing type comprising a translucent panel which is divided into a substantial number of individually lightable areas by an egg crate" structure on the back side thereof, there being a small lamp provided in each compartment thereof, and electrical switch means for energizing the lamps individually or in predetermined groups under the control of the instructor or operator.

A further object of this invention is the provision of novel control circuitry including pushbuttons for selecting the particular configuration of display lamps to be lighted, the pushbuttons including indicator lamps which are energized to indicate which of a number of configurations is being displayed.

Yet another object is the provision of a remote control switch for advancing the program irrespective of the pushbuttons, but which actuates circuitry to illuminate the pushbutton corresponding to the display selected by the remote control switch.

Still another object of this invention is the provision of a display device of the foregoing character and further comprising means whereby a student can effect illumination of a particular selected area of the panel without otherwise disturbing the display configuration then illuminated.

The invention may be further said to reside in certain constructions and combinations of parts which will become apparent from the following description of a preferred embodiment thereof when read in conjunction with the accompanying sheets of drawings forming a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. I is a perspective illustration of a back-lighted universal display device embodying the present invention;

FIG. 2 is an enlarged fragmentary view of a portion of the device of FIG. 1, with parts broken away;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIGS. 4a and 4b are schematic illustrations of control circuitry of the device of FIG. 1; and

FIG. 5 is a fragmentary view of a program plug board.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the form of the invention illustrated in the drawings and described hereinafter, there is provided a display device 10 comprising a generally rectangular frame 12 which is conveniently formed of wood and includes top and bottom walls 14 and 16, end walls 18 and 20, and a narrow, front wall 22 adjacent the end wall 18. A rectangular, translucent panel 26 is supported in the frame 12, the panel 26 being preferably formed of a relatively rigid plastic sheet material.

Below the panel 26 are access doors 28 and 30 behind which are respectively located electrical circuit components and program switch drum and patch board storage compartments. The frame 12 is conveniently adjustably mounted on supports 32 which permit variations in height of the device 10.

Mounted on the front wall 22 are various controls for operation of the device 10, which controls include an array of pushbuttons 36, off and on switches 38, 40, a brightness control 42, a mode select switch 43, and a single step switch 44. A remote single step switch 46 is provided at the end of a suitable electrical cable 48 which has a plug received in a jack on the end wall 18. This remote stepping switch permits an instructor to advance the illumination program from various positions in the classroom.

Congruently mounted over the panel 26 is an overlay panel 50 on which there has been drawn a diagram or the like, portions of which are to be illuminated during a classroom lecture, for example. Thus, there is illustrated on the overlay panel 50 a series of representative diagram blocks A, B, and C which are to be illuminated in sequence as the instructor progresses with his presentation. Extra overlay panels 50' are adapted to be stored at the rear of the device 10 by sliding in grooves 52 as shown.

As is best illustrated in FIGS. 2 and 3, there are provided on the rear side of the panel 26 an egg crate type of structure comprising intersecting horizontal walls 54 and vertical walls 56. The walls 54, 56 define cells or cubicles or components 58, which, in the present example, divide the panel 26 into square areas of about 2 inches on each side. Thus, with a panel 26 of about 4 feet high by 7 feet long, there are 966 panel areas, each associated with a cubicle 58.

The cubicles 58 are closed at the rear by a panel 60 which provides support for lamp sockets 62, one for each cubicle. Alternatively, the panel 60 may be omitted and the lamp sockets 62 mounted on the walls 54 or 56. The lamp sockets 62 each contain a lamp 64 having a reflector 66 which may or may not be integral with the lamp. Energization of any one such lamp 64 will effect transmission of light by the area of the translucent panel 26 served by the cubicle containing the energized lamp.

Also mounted in each cubicle, preferably in an upper corner thereof, is a socket or jack-type switch 70 which has an opening aligned with an opening 72 in the panel 26 and with an opening 74 in an overlay panel 50. The aligned openings 72, 74 permit a plug 76 to be inserted into the switch 70 which is thereby actuated to energize the associated lamp 64, as well as others in some circumstances, all as will be explained in greater detail as this specification proceeds.

Referring now to the schematic illustration of FIGS. 40 and 4b, four of the 60 pushbuttons 36 of the preferred embodiment are shown, namely buttons 1, 2, 3, and 60. The pushbuttons 36 each comprise a button-illuminating lamp 74 and normally closed contacts 76. When a pushbutton 36 is pushed,

the contacts 76 thereof are actuated to an open condition. The buttons 36 are interlocked, as indicated by dotted lines 78, so that pushing of any one button to a latched-in position will cause any previously latched button to pop out to its normal position. This interlocking may be effected entirely mechanically or mechanically within each row and by solenoid from one row to the next, all as is well understood by those skilled in the art of pushbutton switches.

The pushbuttons 36 serve to control operation of a solenoid operated stepping switch 80 which in turn controls operation of a solenoid-operated program switch 82 to ultimately effect energization of certain ones of the panel area illuminating lamps 64 predetermined by a removable patch board 84 later described in more detail. The stepping switch 80 and the program switch 82 are conveniently of the rotary type although they are schematically illustrated in FIG. 4a in a linear manner for convenience.

The stepping switch 80 comprises a solenoid 86 which is linked to contactors 88, 90, and 92 which are moved in unison in step-by-step fashion by energization of the solenoid 86 so as to cooperate with three sets of contacts 94, 96, and 98, each corresponding in number to the number of pushbuttons 36. The solenoid 86 is also linked to interrupter contacts 100 which causes the stepping switch 80 to repeatedly self-step as long as power is applied to input conductors 102 and 104 thereof. I

The contacts 94 serve tocontrol energization of the lamps 74 so that the pushbuttons 36 will be lighted and extinguished sequentially as the device is put through its program. To this end, a lamp power supply 110 is provided which is connected to receive conventional ll5 volt AC electric current from power lines L1 and L2, and provides across lines 112 and 114 a voltage suitable for energizing lamps 64 and 74. This voltage is preferably onthe order of 12 volts DC, and can be regulated to some extent by the knob 42 of a brightness control 116.

The lamp supply voltage is applied via line 112 to each of the lamps 74 which are connected by lines 118 to the individual contacts 94 of the stepping switch 80. Accordingly, the lamp 74 corresponding to the position of the stepping switch 80 will be energized. In the condition illustrated in FIG. 4a, wherein the second pushbutton 36 is latched-in, a circuit may be traced from the lamp power supply 110 through line 112, the lamp 74 of the second pushbutton, the line 118, contacts 94, the contactor 88, a line 120, and line 114 to the lamp power supply.

The program switch 82 operates as a slave to the stepping switch 80 and comprises a solenoid 124 which is linked to a contactor 126. The contactor 126, which is conveniently in the form of a removable drum (not shown) of a well-known construction, is adapted to be stepped to effect closure of a plurality of contacts 128 corresponding to the 60 pushbuttons 36. The solenoid 124 is also linked to interrupter contacts 130 which serve to prevent the stepping switch 80 from operating at a rate different from the program switch. The contacts 130 are connected by the line 104 to the interrupter contacts 100 of the stepping switch 80, and by line 134 to each'of the contacts 96 of the stepping switch.

The program switch solenoid 124 is connected by line 134 to the power line Li, and by line 138 to one side of each of the contacts 98 of the stepping switch 80. The other sides of the contacts 98 are connected by line 140 to the power line L2.

Now, when a different pushbutton 36 is pushed, such as the third button, the contacts 76 thereof will be opened, and the contacts 76 of the second pushbutton will close. Closing of the latter contacts 76 completes a circuit which may be traced from the power line Ll through line 102, solenoid 86, interrupter contacts 100, line 104, contacts 130, line 134, contacts 96 and 90, a line 142, the now closed contacts 76 of the second pushbutton, a line 144, a mode selecting switch 43, and a line 148 to the power line L2. Energization of the solenoid 86 by the just-traced circuit will effect movement of the contactors 88, 90, and 92 to positions corresponding to the third pushbutton where the solenoid 86 will remain deenergized because of the open contacts 76 at the third pushbutton. This movement of the contactors will effect deenergization of the lamp 74 in the second pushbutton and effect energization of the lamp in the third pushbutton. Also, the contactor 92 will effect energization of the solenoid 124 advancing the contactor 126 to the position of contacts 128 corresponding to the third pushbutton.

If some pushbutton beyond the third had been pushed, the contacts 76 of all buttons except the one pushed would be closed, and the self-stepping or interrupter contacts would have caused the solenoid 86 to repeatedly step until the contactor 96 came to the position corresponding to the pushbutton which was pushed and therefore has open contacts 76. Moreover, the program switch 82 would be stepped upon each arrival of the contactor 92 at a set of contacts 98. Thus, it will be seen that when the mode selecting switch 43 is in the auto position, the switches 80 and 82 will always step to the position selected by pushing one of the pushbuttons 36.

The position of the contactor 126 of the program switch 82, together with patch wiring on the patch board 84, determines which one or ones of the lamps 64 will be energized at any time. The patch board 84 comprises a series of jacks 160, each of which is connected by a conductor 162 to one of the contacts 128 of the program switch 82. Thus, there is a patch board jack 160 to each of the 60 positions of the stepping switch 80 and program switch 82.

The patch board further comprises a plurality of shorting buses 164, each of which is provided with a plurality of interconnected jacks 166. These shorting buses may number as many as the number of pushbutton switches, although a lesser number may suffice. In addition, the patch board comprises a plurality of jacks 168, one for each of the lamps 64 which, as has been mentioned earlier, number 966 in the preferred embodiment. Each patch board jack 168 is connected by a conductor 170 to one side of a corresponding one of the 966 lamps 64. The other side of each lamp 64 is connected to a conductor 172 which is connected to the lamp power supply output line 112.

The individual buses 164 are adapted to be connected to selected contacts 128 of the program switch 82 by means of conductive patch cords 176 having suitable plugs at opposite ends for engagement in the jacks and 166. The individual lamps 64 which are to be energized for any given position of the contactor 126 of the program switch 82 are effectively connected to the appropriate bus 164 by means of patch cords 178 between the jacks 166 and 168.

Thus, the three lamps 64 in the group designated A are all electrically connected through the patch board 84 and associated patch cords to the contacts 128 of the program switch 82 corresponding to the first pushbutton 36. The two lamps 64 in the group designated B are both electrically connected through the patch board 84 to the contacts 128 corresponding to the second pushbutton 36. Likewise, the two lamps 64 of the group C are connected to the contacts 128 corresponding to the third pushbutton. Similarly, other groups of lamps 64 may be connected through the patch board 84 to contacts of the program switch 82 corresponding to others of the pushbuttons in accordance with a predetermined program and overlay 50.

With the second pushbutton 36 in its illustrated latched-in condition and the contactor 126 in its illustrated position, the lamps 64 of the group B will be energized as well as the lamp 74 of the second pushbutton. [f the third pushbutton is then depressed, the contactor 126 will move to the third set of contacts 128, deenergizing the lamps of the group B and energizing the lamps of the group C (as well as the lamp 74 of the third pushbutton).

The patch board 84 is preferably removable and may be replaced by substitute patch boards which have been prepared with patch cords to provide desired programs corresponding to the other overlays 50'.

The device comprises circuitry in association with the lamp power supply 110 to permit manual selection of the brightness of the display, to prevent damage to switch contacts because of inrush current when a substantial number of lamps 64 are to be energized at once, and to prevent flicker or flashing of the lamps when the program switch 82 is stepped through a numberof positions before coming to rest in a selected position. To these ends, the lamp power supply must have a remote program capability. Accordingly, the output line 112 is connected internally of the supply to a resistor 190 which is connected in series with a conductor 192, a resistor 194, a variable resistor 196 of the brightness control 116, and a conductor 198 which is connected internally of the power lamp supply to the line 114. A capacitor 200 is connected between the lines 192 and 198, and contacts 204 of an an-- tifiicker relay 206 are connected in parallel with the capacitor 200. The relay 206 comprises a solenoid 208 which is connected on one side by a line 210 to power line L1, and on the other side by a line 212 and line 104 to the interrupter contacts 130 operated by solenoid 124 of the program switch 82.

When the output voltage across lines 112, 114 is to be zero, the contacts 204 are closed, effectively shorting the lines 112, 114. When the contacts 204 open, the capacitor 200 will be charged through resistor 190 over a period of 100 to 300 milliseconds, and the output voltage across lines 112, 114 will increase at the same rate as the capacitor charges. The settings of the variable resistor 196 will determine the maximum output voltage across lines 112, 114.

It will be noted that the contacts 204 of relay 206 will be closed when the stepping switch 80 passes through positions wherein the pushbutton contacts 76 are closed. When the stepping switch contactor.90 arrives at a position having a missing ground," that is, where contacts 76 are open, the selfstepping action ceases and contacts 204 will open permitting the selected lamps 64 to be energized with a voltage which increases at a rate determined by resistor 190 and capacitor 200 to a maximum determined by resistor 196.

At times it is desirable to advance the program in a single step manner without use of the pushbuttons 36, for example, through the use of the earlier mentioned remote switch 46. To this end, the cable 48 comprises conductors 220, 222 connected to lines L2 and 104 respectively. When it is desired to operate in the single step manner without use of the pushbuttons, the mode switch 146 is moved to its open, dotted line position. Thereafter, momentary closing of the remote switch 46 will cause the stepping switch 80 and program switch 82 to advance one position irrespective of the condition of the pushbuttons 36. it will be noted, however, that the pushbutton lamp 74 corresponding to the actual position of the stepping switch 80 and program switch 82 will be energized, thereby always providing the proper indication of what step in the program is being displayed by the lamps 64.

The single step 44 mounted on the front of the device 10 is connected in parallel with the switch 46 to permit single stepping of the program without the remote switch 46, if desired.

When student participation is desired, for example, where an instructor calls upon a student to point out a particular element, say area C, to the class, the student may illuminate that area, or any other, by inserting the plug 76 into one of the holes 74 in the overlay within that area. This will close the switch 70 associated with one of the lamps 64 in the area selected and a circuit may be traced from the power supply 110 through conductor 112, conductor 172, the lamp 64 associated with the switch 70, a conductor 226, a conductor 228, and conductor 114 to the power supply. Because each of the lamps 64 of an area, such as area A, have the side connected to the respective switches 70 also connected together through the associated bus 164, all of the lamps 64 will be energized in any area in which one of the switches 70 is closed.

From the foregoing detailed description of a presently preferred embodiment of the invention, it will be appreciated that the device 10 has accomplished all of the previously stated objects and advantages, as well as others apparent from this description. Of course it will also be appreciated that the described preferred embodiment is given by way of example only.

I claim:

1. A programmable display panel device comprising:

a panel of light-transmitting material having front and rear surfaces;

wall means extending from said rear surface and defining a plurality of cubicles;

a plurality of panel-illuminating lamps, one of said lamps being mounted in each of said cubicles so as to illuminate the area of said panel associated therewith when energized;

a source of lamp-energizing voltage;

program switch means connected to said source of lampenergizing voltage and comprising program switch contactor means, a plurality of program switch contacts, and program switch solenoid means energizable to move said contactor means between said program switch contacts;

electrical connector means electrically connecting predetermined ones of said lamps to predetermined ones of said programswitch contacts for energization in accordance with the position of said contactor means;

selector switch means including control means having a plurality of control positions and comprising a plurality of sets of normally closed contacts, one set being operable to an open condition for each of said control positions;

stepping switch means comprising stepping switch contactor means, a plurality of stepping switch contacts, stepping switch solenoid means energizeable to move said stepping switch contactor means between positions engaging said stepping switch contacts, self-stepping contacts operative by said stepping switch solenoid means; and

said stepping switch solenoid means being connected to said sets of normally closed contacts of said selector switch means and said program switch solenoid means being connected to said stepping switch contacts, whereby operation of said selector switch to a selected one of said control positions will open a corresponding one of said normally closed sets of contacts and close any previously opened sets thereof to energize said stepping switch solenoid to step said stepping switch contactor until it stops on the stepping switch contacts corresponding in position to the opened one of said sets of normally closed contacts, and stepping of said stepping switch contactor will energize said program switch solenoid to step said pro gram switch contactor to a corresponding position with respect to said program switch contacts so as to energize predetermined panel-illuminating lamps corresponding to said selected one of said control positions.

2. A programmable display panel device as defined in claim 1, and wherein:

said electrical connector means comprises patch board means including first socket means connected to each of said panel-illuminating lamps, second socket means connected to said program switch contacts, and a plurality of bus means; and

patch cord means for selectively electrically connecting said first and second socket means to said bus means,

3. A programmable display panel device as defined in claim 1, and wherein said selector switch control means comprises a plurality of pushbuttons corresponding in number to said control positions, each of said sets of normally closed contacts being operable to an open condition by actuation of one of said pushbuttons.

4. A programmable display panel device as defined in claim 3, and wherein:

said selector switch means includes a plurality of indicator lamps each associated with one of said pushbuttons; and

said stepping switch contacts including a plurality of indicator lamp energizing contacts each connected to one of said indicator lamps, and said stepping switch contactor means including a contactor operative to connect said source of lamp voltage to the indicator lamp corresponding tosaid selected one of said operative positions of said selector switch means.

5. A programmable display panel device as defined in claim 2, and wherein said selector switch control means comprises a plurality of pushbuttons corresponding in number to said control positions, each of said sets of normaLly closed contacts being operable to an open condition by actuation of one of said pushbuttons.

6. A programmable display panel device as defined in claim 5, and wherein:

said selector switch means includes a plurality of indicator lamps each associated with one of said pushbuttons;

said stepping switch contacts including a plurality of indicator lamp energizing contacts each connected to one of said indicator lamps, and said stepping switch contactor means including a contactor operative to connect said source of lamp voltage to the indicator lamp corresponding to said selected one of said operative positions of said selector switch means. 1

7. A programmable display panel device as defined in claim 6, and wherein said lamp voltage supply means comprises adjustable means for varying the maximum value of said voltage to select the brightness of said lamps, and means for reducing said voltage to zero during stepping of said program switch means to eliminate flicker of said panel lamps.

8. A programmable display panel device as defined in claim 7, and wherein said lamp voltage supply means comprises means for limiting the rate at which said voltage reaches said maximum voltage when said program switch means stops at a position corresponding to a position selected by said selector switch means.

9. A programmable display panel device as defined in claim 8, and further comprising:

a mode-selecting switch operative between a pushbutton mode position and a single step mode position, and operative in the latter position to interrupt current flow through any of said sets of contacts of said selector switch means; and

a single step control switch operative to advance said stepping switch a single step for each actuation of said single step control switch.

10 A programmable display panel device as defined in claim 2, and further comprising:

a plurality of additional switch means each mounted in one of said cubicles;

said additional switch means each being connected between the side of the corresponding panel-illuminating lamp which is connected to said patch board means and said source of lamp energizing voltage;

said additional switch means each being normally open; and

said additional switch means each being individually operable from said front side of said panel to a closed position whereby the associated panel lamps can be selectively energized irrespective of the operative position of said program switch.

11. A programmable display panel device as defined in claim 10, and further comprising:

frame means supporting said panel;

overlay means supported by said frame means in superimposed relation to said panel; and

said frame comprising storage means for other overlay means.

12. A programmable display as defined in claim ll, and comprising means for operating said additional switch means to their closed positions through said overlay means when one of said overlay means is in said superimposed relation. 

1. A programmable display panel device comprising: a panel of light-transmitting material having front and rear surfaces; wall means extending from said rear surface and defining a plurality of cubicles; a plurality of panel-illuminating lamps, one of said lamps being mounted in each of said cubicles so as to illuminate the area of said panel associated therewith when energized; a source of lamp-energizing voltage; program switch means connected to said source of lamp-energizing voltage and comprising program switch contactor means, a plurality of program switch contacts, and program switch solenoid means energizable to move said contactor means between said program switch contacts; electrical connector means electrically connecting predetermined ones of said lamps to predetermined ones of said program switch contacts for energization in accordance with the position of said contactor means; selector switch means including control means having a plurality of control positions and comprising a plurality of sets of normally closed contacts, one set being operable to an open condition for each of said control positions; stepping switch means comprising stepping switch contactor means, a plurality of stepping switch contacts, stepping switch solenoid means energizeable to move said stepping switch contactor means between positions engaging said stepping switch contacts, self-stepping contacts operative by said stepping switch solenoid means; and said stepping switch solenoid means being connected to said sets of normally closed contacts of said selector switch Means and said program switch solenoid means being connected to said stepping switch contacts, whereby operation of said selector switch to a selected one of said control positions will open a corresponding one of said normally closed sets of contacts and close any previously opened sets thereof to energize said stepping switch solenoid to step said stepping switch contactor until it stops on the stepping switch contacts corresponding in position to the opened one of said sets of normally closed contacts, and stepping of said stepping switch contactor will energize said program switch solenoid to step said program switch contactor to a corresponding position with respect to said program switch contacts so as to energize predetermined panel-illuminating lamps corresponding to said selected one of said control positions.
 2. A programmable display panel device as defined in claim 1, and wherein: said electrical connector means comprises patch board means including first socket means connected to each of said panel-illuminating lamps, second socket means connected to said program switch contacts, and a plurality of bus means; and patch cord means for selectively electrically connecting said first and second socket means to said bus means.
 3. A programmable display panel device as defined in claim 1, and wherein said selector switch control means comprises a plurality of pushbuttons corresponding in number to said control positions, each of said sets of normally closed contacts being operable to an open condition by actuation of one of said pushbuttons.
 4. A programmable display panel device as defined in claim 3, and wherein: said selector switch means includes a plurality of indicator lamps each associated with one of said pushbuttons; and said stepping switch contacts including a plurality of indicator lamp energizing contacts each connected to one of said indicator lamps, and said stepping switch contactor means including a contactor operative to connect said source of lamp voltage to the indicator lamp corresponding to said selected one of said operative positions of said selector switch means.
 5. A programmable display panel device as defined in claim 2, and wherein said selector switch control means comprises a plurality of pushbuttons corresponding in number to said control positions, each of said sets of normaLly closed contacts being operable to an open condition by actuation of one of said pushbuttons.
 6. A programmable display panel device as defined in claim 5, and wherein: said selector switch means includes a plurality of indicator lamps each associated with one of said pushbuttons; said stepping switch contacts including a plurality of indicator lamp energizing contacts each connected to one of said indicator lamps, and said stepping switch contactor means including a contactor operative to connect said source of lamp voltage to the indicator lamp corresponding to said selected one of said operative positions of said selector switch means.
 7. A programmable display panel device as defined in claim 6, and wherein said lamp voltage supply means comprises adjustable means for varying the maximum value of said voltage to select the brightness of said lamps, and means for reducing said voltage to zero during stepping of said program switch means to eliminate flicker of said panel lamps.
 8. A programmable display panel device as defined in claim 7, and wherein said lamp voltage supply means comprises means for limiting the rate at which said voltage reaches said maximum voltage when said program switch means stops at a position corresponding to a position selected by said selector switch means.
 9. A programmable display panel device as defined in claim 8, and further comprising: a mode-selecting switch operative between a pushbutton mode position and a single step mode position, and operative in the latter position to interrupt current flow through any of said sets of contacts of said selector switch meAns; and a single step control switch operative to advance said stepping switch a single step for each actuation of said single step control switch. 10 A programmable display panel device as defined in claim 2, and further comprising: a plurality of additional switch means each mounted in one of said cubicles; said additional switch means each being connected between the side of the corresponding panel-illuminating lamp which is connected to said patch board means and said source of lamp energizing voltage; said additional switch means each being normally open; and said additional switch means each being individually operable from said front side of said panel to a closed position whereby the associated panel lamps can be selectively energized irrespective of the operative position of said program switch.
 11. A programmable display panel device as defined in claim 10, and further comprising: frame means supporting said panel; overlay means supported by said frame means in superimposed relation to said panel; and said frame comprising storage means for other overlay means.
 12. A programmable display as defined in claim 11, and comprising means for operating said additional switch means to their closed positions through said overlay means when one of said overlay means is in said superimposed relation. 